Improvement in screw-cutting attachments for lathes



W. GLEASON. Screw-Cutting Attachments for Lathes.

N0. 143,898. I Patented 0ct.21,1873.

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UNITED STATES WILLIAM GLEASOIN, on nocnnsrna, new YORK, ASSIGNOR or ONEHALF PATENT OFFIc.

HIS RIGHT TO KIDD IRON WORKS COMPANY, OF SAME PLACE.

IMPROVEMENT IN SCREW-CUTTING ATTACHMENTS FOR LATHES.

Specification forming part of Letters Patent No. 143.898, dated October 21,1873; application filed September 22, 1873.

To all whom it may concern! Be it known that 1, WILLIAM GLEAsoN, of Rochester, in the county of Monroe and State of New York, have invented certain Improvements in Screw-Outtin g Attachment for Lathes, of which the following is a specification:

This invention relates to 'lathes which may be used for cutting screw-threads and it consists, essentially, in connecting, by suitable mechanical means, the tool-stock of such lathes with the shear-nut, whereby, when the nut is opened by the operator, the tool or cutter shall be withdrawn from its work by the same movement and at the same instant.

Figure 1 is a front elevation of a portion of the sliding tool-rest of an ordinary engine lathe having my invention attached. Fig. 2 is a transverse vertical section of the same on line 00. Fig. 3 is a similar view on line y. Fig. 4 is a top view of the adjusting-segment 13. Figs. 5 and 6 are modifications of my invention.

When cutting screw-threads in the ordinary engine-lathes, as heretofore constructed, the greatest care and attention are required on the part of the operator in returning the tool to its place after a out has been made, which should I be done at the same time that the shear-nut is closed upon the feed-screw, the one operation being performed with onehand and the other with the other. The object of this invention is to enable him, with one hand, to withdraw the cutting-tool and open the nut at the same instant, and vice versa.

'In applying my invention, I provide the feed-screw b of the tool-stock with a loose sleeve, to, fitted between the fixed and loose collars c and c, or both collars may be fixed, if desired. The sleeve is allowed to slidewithin the arch d, carrying the screw with it, but is prevented from turning with the screw by the stud f, which moves in a mortise, at i, running parallel with the screw. This stud f reaches into the sinuous grooye g, Figs. 3 and 4, in the circumferential. face of the segment B, which groove and stud govern the longitudinal movements and position of the screw. The segment B is pivoted centrally to the apron A of the sliding rest R, and the lower end is which latter is carried by the double-flanged pulley h. The rack gears into a pinion, p, which is fixed upon the shaft t, by which the ordinary shear-nut N of engine-lathes is opened and closed. When the segment B is in the position shown in Fig. 1, the feed-screw b and tool-stock k will occupy the position shown in full hues in Fig. 3, the stud f resting in that end of the sinuous groove shown at n, Fig. 4.

The tool is withdrawn from its working po sition, and the shear-nut N is opened from the head of the lathe, when the desired set of the cutting-tool may be regulated, for the next cut, by a partial turnof the screw 1) by the handle H. The parts are then thrown into their working position by a partial backward'turn of the crank-handle on the shaft t.

It will be seen that, with this attachment, the operator can set the tool in, or withdraw it from, its work at any desired point along the screw.

When inside threads are to be cut the pulley h is removed and placed above the pinion, causing the upper half of the rack D to be thrown into gear with the pinion, which of course would reverse the order of the movement of the cuttingtool in relation to those of the shear-nut.

Various other mechanical means might be employed for connecting the nut N and toolstoek It, so ,as to impart to them a simultane- 'out an essential departure from the character which a spur-wheel is applied in place of the pinion p, and one hung upon the feed-screw b, with a sort of cam projection upon each side, to work against similar cams on the collar a, and one or more intermediate gear-wheels.

Another modification, and which would probably be preferable, is shown in Fig. 6, and consists in the employment of a wristpin and connecting-link instead of rack and pinion. In this construction the upper end of the pivoted lever connects with a sliding plate, in

hinged to the arm 0 of the double rack D,

feed-screw S of the lathe by a partial forward turn of shaft t. It will be seen that this per- Inits the tool-stock 7a to be returned toward the ous movement, when changes are made, with-.

of my invention. One is shown in,Fig. 5, in

which is formed the diagonal groove for the feed-screw b and adjusting cam B, or its equivstud of the sleeve to Work in. alent, in combination with the shear-nut N and. What I claim as my invention isintermediate mechanism, operating conj ointly, 1. As an improvement in screw-cutting atsubstantially in the manner and for the purtachments to lathes, the cam-lever B, in composes set forth.

bination with the sliding sleeve a, feed-screw WILLIAM GLEASON. b, and tool-stock 70, all acting conjointly sub- Witnesses: stantially as and for the purposes set forth. WM. S. LOUGHBOROUGH,

2. The longitudinally-adjustable tool-stock DANIEL W001). 

